The articles of furniture such as the aforementioned ones to which the present invention could be applied, are normally composed by a support and a padding. The support could be made from wood, metal or plastic material and comprise at least one frame to which are fixed the aforesaid structures or the means of suspension destined to support, at least in part, the human body.
The suspension structure could be produced by a variety of techniques known in the art, for instance from a plurality of metal springs, from strips of leather or wooden battens connected transversely to the frame. In some cases cloth straps are used, provided where necessary with the means for varying the tension of said straps. However, these structures often present problems owing to the complexity of the assembly operations. Moreover, the aforementioned techniques often don't give optimum durability characteristics to the product.
A second type of suspension provides for the use of pre-tensioned elastic-interwoven straps, which are applied to the frame during manufacture of the article of furniture. The straps are applied to the frame in predetermined positions, often with a crossing pattern. Solutions of this type, while presenting better reliability and better durability, don't give the finished product the classic padded upholstered effect which can be obtained with metal springs, and which is much appreciated by buyers, both for its aesthetic value and for the impression it offers of better anatomical adaptability to the seated position.
The Patent Application PCT WO 96/14782 in the name of the applicant describes a system of suspension comprising at least one elastic-interwoven strap, which is fixed, in pre-tensioned condition, above a rigid U-shaped support. This U-shaped support is fixed to the frame of the article and one or more springs in compression are inserted between the base of the U-shaped support and the strap in tension, in adjustable positions.
Such structure produces an upholstered effect of the type obtainable with traditional springs. Moreover, assembly of the suspension structure does not have to be to carried out by the manufacturer, being an operation that could be done instead by the buyer or the wholesaler. The latter solution however requires of the use of at least one rigid element, for instance an angle-iron, which is generally expensive.